Lumen

photo courtesy of Spencer Greet


October 10, 2008


I find myself preoccupied with light these days.

The sunlight in the fall, perhaps because of the increasingly oblique angle of the sun, seems to illuminate the outside world more richly and with more contrast than the light in the summer. From my perch at the computer, I can see verdant grass, turning leaves, and elongated shadows. The air is very clear, and the sky is periwinkle without a trace of clouds. Houses, trees, chrysanthemums on the lawn - all have a vivid, painterly quality. You just want to drink it in.

Inside the house, due to recent renovations, there are many recessed ceiling lights. Before the kitchen was re-done, it was lighted mostly by a large traditional fluorescent ceiling light. It gave the kind of light that fluorescent lighting gives - strangely cold, and harsh. The new lights are incandescent floods with rheostats on them; these lights have the mellower, softer quality associated with incandescent lighting.

At first, we were thinking about putting the newer type of fluorescent flood lamp in the ceiling lights. Traditional incandescent lights use more energy because much of the energy they use is consumed by the production of heat rather than light. Mindful of the need for all of us to be more prudent about energy consumption, we thought that the switch to fluorescent would be a good thing. New fluorescents are available whose spectrum of light is closer to incandescent, or the full-spectrum light of daylight.

We routinely dim the lights at night when some of us go to bed, and others are still out, so that the latecomers will not come in to a dark house. It seems wasteful to leave a lot of lights on at full blast when no one is in the room, and the rheostats reduce the amount of energy used by the bulbs. I also like the dimmed light as it gets closer to bedtime; it helps to get into the frame of mind for sleep.

Plus, dimmed incandescent lighting is so much better for the appearance of les femmes d'une certaine age. It makes us look like fitting subjects for a painting by Rembrandt, or Renoir. Of course, candlelight cherishes mature female skin more than any light, but is too impractical for everyday use.

Regrettably, fluorescent lights cannot be dimmed, at least by the use of a traditional rheostat.


Another potential issue with fluorescent bulbs is the mercury they contain. The electrician who installed the new lighting made me aware of this issue. According to some scientists, though, the amount of mercury contained in the bulbs is miniscule, and the bulbs just need to be recycled properly.


The buildup of heat around the base of the fluorescent lamp is also problematic; these bulbs need ventilation, which they do not get in recessed ceiling lighting. The buildup of heat means that the bulb will not last as long.


We have switched to compact flurescent bulbs in table lamps with shades, and other areas where there is adequate ventilation. We are continuing to use the incandescent floods with dimmers in our ceiling lights, until the technology of dimmable fluorescent bulbs has been worked out. And we let the sunshine in while we still have it.